1. Field of the Invention
This invention relates generally to article or material handling and transfer systems for moving articles, equipment or goods from one location to another and relates specifically to material handling systems which include a plurality of plate members which are positioned in spaced relationship with one another so as to create a network of passageways therebetween. The network of passageways will define a plurality of routes between locations thereby insuring that materials may be transferred between locations even though one or more passageways or routes are impassable. Carriages conveying the articles, equipment or goods are selectively moved along the various and optional routes defined by the passageways as they are supported by the plate members so that materials may be transferred or positioned in substantially any desired location within the area defined by the system.
2. History of the Art
Many efforts have been made to create structures, mechanisms and systems for facilitating the movement and/or transfer of materials and articles including crates, machinery, parts, packages and other loads from one place or position to another. Some prior art structures include self-propelled vehicles including mobile lifts or cranes such as disclosed in U.S. Pat. No. 3,059,782 to Baudhuin. Although mobile cranes and lifts of the type shown in Baudhuin may be used to elevate and transfer heavy loads, such structures are large and bulky and are not easily maneuverable and, therefore, are not well suited for many uses.
Other types of material, work or object elevating and transferring mechanisms include fixed rail overhead cranes. Some examples of these structures are disclosed in U.S. Pat. Nos. 2,932,413 to Chanut and 3,786,936 to Staadt. These systems utilize carriages and lifts which are movable along a first direction defined by generally parallel primary support rails suspended from the walls and ceiling of a building. The carriages may also be supported for movement in a second direction by mounting such carriages on secondary support rails which extend perpendicularly with respect to the primary support rails and which themselves are movable along the primary rails. Again, such lift and transfer systems are limited in their usefulness. Such systems do not permit multiple carriages to operate along the same rail system simultaneously or without undue interference and are also further limited in that if a rail or carriage member is damaged or becomes inoperative, the entire system cannot be used.
In addition to the foregoing, other types of crane supports have been designed to provide increased flexibility in the movement of article transfer systems or cranes. In U.S. Pat. No. 748,328 to Wilke, a system is shown wherein rails are positioned in a generally perpendicular grid pattern with turntables being provided at each rail intersection. This structure permits cranes having pivoted wheel assemblies to be transferred from a first pair of tracks or rails to a perpendicular pair of rails. Such turntable mechanisms are awkward and not effectively used as four separate turntables must be rotated before a change in the direction of movement can be achieved.
More recently, warehouses and other facilities have begun using a system of floor oriented open tracks or rails to provide channels for automatically guiding motorized dollies from one location to a preselected destination in the warehouse. The dollies include guidance members which are disposed within or cooperatively engage the tracks or rails in such a manner that they will cause the dollies to follow only preselected paths. As with other prior art material transfer systems, these systems are hampered by the breakdown of any portion or part of the system. Should a dolly stop and block a path or a rail or channel becomes obstructed, the transfer of materials using other dollies is no longer possible.